The state of venous and arterial cerebral hemodynamics was studied using ultrasonic dopplerography with application of hypo- and hypercapnia, angioencephaloscintigraphy with pertecnetate Tc-99m in 48 patients with syndrome of vertebrobasilar insufficiency. Estimation was performed in patients by the results of neurological and otoneurologic evidence, the data of nistagmography and registration of the truncal evoked potentials. It was found that at early stages of the development of vertebrobasilar insufficiency's syndrome disorders of vasomotor reactivity and disturbances in venous hemodynamics play a leading role in its pathogenesis. Stenosis damages of extra- and intracranial arteries become dominating in subsequent clinical picture.